Method of and apparatus for treating water utilizing proton-releasing substance and/or magnetic field

ABSTRACT

A method of and an apparatus for treating water by providing a water being treated with a crystal water-containing proton-releasing crystalline mineral and/or a magnetic field, while controlling the amount of proton released and the strength of said magnetic field as control indicators so as to remove, reduce, vanish or deproliferate the cations, a part of the anions, eutrophicated substances, chlorophyll, algae, bacteria and the like which are contained in the water by flocculating them, making them adsorbed to flocs or making them colloidal.

TECHNICAL FIELD

The present invention relates to a method of an apparatus for treatingwater adopted for, for example, purification of various waters includingagricultural effluent, domestic waste water, the water of a closed waterarea, the water of a fish pond (algae-containing water), mixed water ofdomestic waste water and sea water, sea water and underground water, andsoftening of hard water. More particularly, the present inventionrelates to a method of and an apparatus for treating water characterizedin that a proton releasing substance and/or a magnetic field areprovided for a water being treated, while controlling the amount ofproton released and/or the strength of the magnetic field as controlindicators so as to remove, reduce, vanish or deproliferate the cations,a part of the anions, eutrophicated substances, chlorophyll, algae,bacteria and the like which are contained in the water, or to removealkali earth metal ions chiefly consisting of calcium ions and magnesiumions from the water to soften hard water.

BACKGROUND ART

Contamination of closed water areas including lakes and marshes andinland seas by phosphorus and eutrophicated substances has now become abig problem not only in Japan but also all over the world. It is wellknown that the progress of such contamination is derived from theeutrophicated substances contained in the agricultural effluent,domestic waste water, etc., which flow into the lakes and marshes andinland seas and the lowering of the water level of the water area due tothe development of coasts.

Accordingly, techniques for restraining eutrophicated substances fromflowing into closed water areas, for example, concentrated treatment ofcity life type domestic waste water, agricultural community waste waterand top soil eluting substances produced by agricultural effluent andrain water, and various techniques for maintaining and enhancing theself purification capacity, for example, techniques of removingdeposited sludges and algae, charging chemical substances such as limeand blowing oxygen or air into the water have been carried out.

As a method of softening hard water, a method of depositing alkali earthmetals (e.g., CaO) by storing the hard water for a certain period,removing the alkali earth metals by distillation or with an ion exchangeresin, and a method of depositing these metals by boiling and using thesupernatant liquid are known.

These prior arts, however, involve the following problems: in the caseof using an absorbent, flocculating agent, neutralizing agent, oxidizingagent, reducing agent, etc., since secondary contaminating substancesare mixed into the treatment water and a large amount of sludge isgenerated, it is necessary to remove them; and in the case of carryingout other techniques, even if a large sum of equipment cost and runningcost is invested, satisfactory effects have not yet been produced.

In a method of storing hard water for a certain period for softeining itin the prior art, if the concentration of the alkali earth metalsdissolved in the water is high, the pH of the water becomes weaklyalkaline in most cases. Therefore, the water is allowed to stand for along time to generate and deposit calcium hydroxide or the like, but thebehaviour is unstable and, further, with the reduction in theconcentration, the amount of deposit produced becomes smaller. On theother hand, in the case of softening water by distillation, with an ionexchange resin, or by boiling, the cost is raised, so that the treatmentof a large amount of water is difficult.

DISCLOSURE OF INVENTION

Accordingly, it is a primary object of the present invention to providea method of and an apparatus for treating water which are capable ofremoving, reducing, vanishing or deproliferating the cations, a part ofthe anions, eutrophicated substances, chlorophyll, algae, bacteria andthe like which are contained in a water being treated by flocculatingthem, making them absorbed to flocs or making them colloidal.

It is another object of the present invention to provide a method fortreating water which prevents secondary contaminating substances frommixing into the water, this phenomenon being inevitable in the priorart, and which produces only a very small amount of sludge.

To achieve this aim, in one aspect of the present invention there isprovided a method of treating water which is capable of removing,reducing, vanishing or deproliferating the cations, a part of theanions, eutrophicated substances, chlorophyll, algae, bacteria and thelike which are contained in the water, by flocculating them, making themabsorbed to flocs or making them colloidal by providing the water beingtreated with a crystal water-containing proton-releasing crystallinemineral and/or a magnetic field while controlling the amount of protonreleased and/or the strength of the magnetic field.

In the present invention, under a medium or low proton condition inwhich a medium or small amount of proton releasing substance is providedfor a water system to such an extent that makes the pH of the waterafter being left to stand for 24 hours not less than 5.6 and under amedium or low magnetic field condition in which the strength of themagnetic field is about 100 to 600 gausses, the cations in the water arereadily flocculated and, hence, removed from the water, and further thephosphate ions are absorbed by the flocs and deposited, thereby beingeliminated from the water system. Under a high proton condition in whicha large amount of proton releasing substance is provided for the watersystem to such an extent that makes the pH of the water after being leftto stand for 24 hours not more than 5.5 and under a high magnetic fieldcondition in which the strength of the magnetic field is, for example,1,000 to 2,000 gausses, the above-described impurities are apt to bemade colloidal, whereby it is possible to obstruct the impurities frombecoming a nutrient source for bacteria and prevent the generation oforganic deposits or reduce the amount of organic deposit. When thecations contained in the water are mainly alkali earth metal ions suchas calcium ions and magnesium ions, if the amount of proton released ismade small or medium and the magnetic field is made a medium or lowmagnetic field having a strength of about 100 to 600 gausses, it ispossible to remove the alkali earth metal ions in the form of flocs,thereby softening the hard water.

In another aspect of the present invention, there is provided a methodof treating water which is capable of removing, reducing, vanishing ordeproliferating the above-described impurities by diluting the treatedwater obtained by the above-described water treating method (i.e.treating water) with a water being treated and diffusing the former intothe latter.

In still another aspect of the present invention, there is provided amethod of treating water by adding cations if the cations for generatingthe flocs for absorption and deposition are insufficient in the treatingwater and/or the water being treated in the above-described watertreating method.

In a further aspect of the present invention, there is provided anapparatus for treating water comprising a water flowing tank or a waterpipe which contains a crystal water-containing proton-releasingcrystalline mineral; an energized coil provided on the outer peripheryof the water flowing tank or the water pipe, or a magnetic material or amagnetism memory provided in the water flowing tank or the water pipe;and a cleaning nozzle which is provided in the water flowing tank or thewater pipe for washing the proton-releasing substance and the flocsadhered to the surface of the magnetic material or the magnetism memorywith air and/or water therethrough.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1 to 4 shows embodiments of an apparatus according to the presentinvention, wherein

FIG. 1A is a vertical sectional view of a treating tank, taken inparallel to the plane including the diameter of a water pipe;

FIG. 1B is a longitudinally vertical sectional view of the water pipeshown in FIG. 1A;

FIG. 2A is a plan view of the structure of a water flowing tank usingdiscal magnets;

FIG. 2B is a vertical sectional view of the structure shown in FIG. 2A;

FIG. 2C is a perspective view of the discal magnets shown in FIG. 2A;

FIG. 3 is a perspective view of a water flowing tank using magnetsheets;

FIG. 4A is a laterally vertical sectional view of a water flowing tankaccommodating cristobalite retaining cylinders 8; and

FIG. 4B is a longitudinally vertical sectional view of the water flowingtank shown in FIG. 4A;

FIG. 5 schematically shows the method of treating water adopting adiluting method;

FIG. 6 schematically shows a test plant adopting the diluting methodshown in FIG. 5;

FIGS. 7 to 14 are graphs showing the behaviour of ions in various kindsof treating waters which are diluted with various kinds of waters beingtreated in Example 4;

FIG. 15 is graphs showing the behaviour of P and N depending upon thedegree of dilution and aging period for each kind of water being treatedin Example 5;

FIGS. 16 and 17 are graphs showing the behaviour of P and N and thelight transmittances of the water of the fish pond subjected to thebatch dilution treatment in Example 6;

FIG. 18 is graphs showing the behaviour of P and N and the lighttransmittances of the water subjected to continuous flowing dilutiontreatment in Example 7;

FIG. 19 is graphs showing the changes with time in the amounts of totalN due to treatment (the upper graph) and changes with time in theamounts of NH₄ due to treatment (the lower graph);

FIG. 20 is a graph showing changes with time in the amounts of total Pdue to treatment;

FIG. 21 is a graph showing changes with time in the amounts of total Fedue to treatment;

FIG. 22 is a graph showing changes with time in the amounts of Ca due totreatment;

FIG. 23 is a graph showing changes with time in COD due to treatment;

FIG. 24 is a graph showing changes with time in the pH value due totreatment;

FIG. 25 is a graph showing magnetic flux density and remaining P;

FIG. 26 is a graph showing magnetic flux density and remaining NH₄ ;

FIG. 27 is a graph showing magnetic flux density and remaining COD; and

FIG. 28 is a graph showing changes in concentration of dissolved Ca.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be explained with reference to the followingexamples, but it is to be understood that the present invention is notlimited thereto.

The crystal water-containing proton-releasing crystalline mineral usedin the following examples is natural cristobalite, but any other mineralthat easily releases protons, for example, synthetic cristobalite andzeolite is usable.

The amount of proton released is freely adjustable in accordance withthe kind of the crystal water-containing proton-releasing crystallinemineral, the amount of water being treated, the time for treating, etc.,and the amount of proton released, namely, whether it is a highly ormiddle/low proton state is determined by measuring the pH value of thewater system which has been provided with a proton-releasing substancesuch as cristobalite and has been allowed to stand for 24 hours. Inother words, the amount of proton released is so controlled as to assumea high proton state having a pH value of not more than 5.5 or a middleor low state having a pH value of not less than 5.6 in accordance withthe purpose of treating the water.

As the material for supplying a magnetic field, ferrite magnets ormagnet sheets (ferrite pressed sheets with N and S poles disposed in areticulate state) were used. Magnetic field was supplied by a method ofplacing a water passage itself in a coil and energizing the coil (themagnetic density can be freely set by varying the number of turns), or amethod of disposing a magnetic material or a magnetism memory in thewater passage in such a manner that the distribution of magnetic flux isaveraged so as to minimize the resistance to the running water (seeFIGS. 1, 2, 3 and 4). As the material of the magnetic material or themagnetism memory, general magnetic material or ferrite, barium ferrite,etc. using a plastic material as a binder are used. The latter ispreferred.

As for the generation of a deposit by supplying a magnetic field, when alow magnetic field is applied together with the release of protons, theflocculation of the cations greatly progresses and, further, a part ofthe anions (phosphate ions) are absorbed by the flocs and deposit. Amagnetic flux density of about 100 to 600 gausses is preferably for theabove-described reaction.

When a high magnetic field is applied together with the release ofprotons, the cations phosphate ions, grease, protein, etc. are madecolloidal so as to be inhibited from becoming a nutrient source forbacteria and to prevent the deposition of organic substances to thebottom of a closed water area, or reduce the amount of deposit.

A magnetic flux density of about 1,000 to 2,000 gausses is preferablefor the above-described reaction.

The use of a synthetic zeolite which releases excessive protons alsoaccelerates the colloidal dispersion like the application of magneticfield of a high magnetic density.

In short, the amount of proton released and the strength of a magneticfield are to be selected in accordance with the purpose of treatingwater.

The analytical method of each element was based on Notification No. 13of the Environment Agency or the JIS analytical method.

More specifically, each element was analyzed in the following way.

1. Phosphorus

Iron standard liquid was added to a sample being analyzed and furthernitric acid and perchloric acid were added thereto. The mixture washeated, concentrated and completely ozidized and the organic substanceswere decomposed. The phosphorus was quantitatively analyzed by themolybdenum blue method.

2. Nitrogen

A sample being analyzed was subjected to colorimetry by theKjeldahl-Nessler method, or the Devarda reduction Kjeldahl-Nesslermethod.

3. Calcium

Hydrochloric acid was added to a sample being analyzed to dissolve theflocs and quantitatively analyzed by the atomic-absorption spectroscopy.

4. Sodium and potassium

Hydrochloric acid and water were added to a sample being analyzed andquantitatively analyzed by the atomic-absorption spectroscopy.

EXAMPLE 1

Investigation on Changes with Time in the Amounts of Phosphorus,Nitrogen Chemical Oxygen Demand (COD), etc, due to the Treatmentaccording to the Present Invention

    __________________________________________________________________________    (Analysis of the Water Examined)          (ppm)                                                                        Trans-                                                                  suspended                                                                           mittance                             COD       T.N                                                                              NH.sub.4                                                                         T.P                                                                              SO.sub.4                                                                         T.Fe                                                                              Ca pH Mg substances                                                                          (%)                                  __________________________________________________________________________    Untreated                                                                           64.3                                                                              22.4                                                                             24.6                                                                             3.20                                                                             31.7                                                                             6.00                                                                              18.0                                                                             7.18                                                                             5.6                                                                              340   96                                   water                                                                         Primary                                                                             16.7                                                                              18.4                                                                             2.0                                                                              1.32                                                                             32.2                                                                             0.87                                                                              17.2                                                                             6.16                                                                             4.1      98                                   treated                                                                       water                                                                         Secondary                                                                           17.7                                                                              21.2                                                                             2.4                                                                              1.52                                                                             32.1                                                                             1.17                                                                              17.6                                                                             6.29                                                                             4.1                                                                              14.6  98                                   treated                                                                       water                                                                         __________________________________________________________________________     Light transmittance was measured on the assumption that the pure water wa     100%.                                                                    

In the experiments in Example 1, the domestic waste water (untreatedwater, primary treated water and secondary treated water of Omi-hachimanCity Housing Development waste-water treating plant) having thecomposition and the chemical values shown in the above-described tablewas examined.

100 g of cristobalite and magnet sheets having a strength of 340 Gausswere collectively charged into a 500-ml beaker such that they came intoclose contact with the inner walls of the beaker, 400 ml of theuntreated water, primary treater water secondary treated water was putinto the respective beakers. The treating time was set sequentiallybetween 30 minutes and 300 minutes, and the lot which had reached thepreset time was immediately filtered through GF/F glass filter paper,and the filtrate from which the flocs were separated was measured toexamine the changes with time in the amounts of phosphorus, nitrogen,the chemical oxygen demand (COD), etc. due to the treatment. The resultsare shown in the following table and FIGS. 19-24.

    __________________________________________________________________________    Time                                                                              Untreated water                                                                              Primary treated water                                                                        Secondary treated water                     (min.)                                                                            RF 30 60 120                                                                              300                                                                              RF 30 60 120                                                                              300                                                                              RF 30 60 120                                                                              300                             __________________________________________________________________________    T.N 22.4                                                                             17.4                                                                             14.8                                                                             12.2                                                                             10.4                                                                             18.4                                                                             16.0                                                                             16.8                                                                             16.0                                                                             15.4                                                                             21.2                                                                             18.2                                                                             17.4                                                                             17.2                                                                             16.8                            NH.sub.4                                                                          24.6                                                                             16.8                                                                             14.0                                                                             12.4                                                                             9.6                                                                              2.0                                                                              tr tr tr tr 2.4                                                                              tr tr tr tr                              T.P 3.20                                                                             1.32                                                                             1.16                                                                             0.90                                                                             0.70                                                                             1.32                                                                             0.44                                                                             0.40                                                                             0.34                                                                             0.26                                                                             1.52                                                                             0.46                                                                             0.34                                                                             0.29                                                                             0.20                            T.Fe                                                                              6.00                                                                             5.32                                                                             4.80                                                                             4.00                                                                             3.40                                                                             0.87                                                                             0.77                                                                             0.60                                                                             0.32                                                                             0.32                                                                             1.17                                                                             0.92                                                                             0.80                                                                             0.40                                                                             0.40                            Ca  18.0                                                                             13.3                                                                             11.3                                                                             9.6                                                                              8.0                                                                              17.2                                                                             15.2                                                                             14.6                                                                             15.2                                                                             14.0                                                                             17.6                                                                             15.1                                                                             14.7                                                                             14.1                                                                             14.1                            COD 64.3                                                                             28.1                                                                             31.7                                                                             32.5                                                                             33.7                                                                             16.7                                                                             16.5                                                                             16.1                                                                             18.2                                                                             16.5                                                                             17.7                                                                             12.8                                                                             9.6                                                                              11.2                                                                             13.2                            pH  7.18                                                                             7.01                                                                             6.86                                                                             6.81                                                                             6.38                                                                             6.10                                                                             5.83                                                                             5.42                                                                             5.44                                                                             5.01                                                                             6.29                                                                             5.80                                                                             5.67                                                                             5.14                                                                             4.87                            __________________________________________________________________________

From the above-described results, it is clear that P, NH₄, Fe and Ca inthe untreated water exhibit the tendency to reduce favorably with theelapse of time. However, in the coexistence of NO₃ (in the case of theprimary treated water and the secondary treated water), a prominenttreating effect is not observed except for P. The untreated watercontains a large amount of organic suspended substances, which assume acolloidal state with the elapse of time, and they are considered to be acause for increasing the COD value.

EXAMPLE 2 Behavior of Ion with Changes in the Maximum MagneticFlux-Density

In the experiments in Example 2, the waters of irrigation ponds in thevicinity of Kakogawa City which had green algae generated were examined.800 ml of the water being examined was put into a 1-l beaker and 200 gof natural cristobalite was added thereto. Magnetic fields of 180, 600and 1,000 Gauss Max were respectively applied to the waters of thebeakers, which were filtered 120 minutes thereafter. The amounts oftotal P and NH₄, the COD value and the light transmittance of eachfiltrate were measured. The results are shown in the following table andFIGS. 25-27.

    __________________________________________________________________________             Maximum                                                                       magnetic                                                                      flux Trans-                                                                   density                                                                            mittance                                                                           Total P NH.sub.4                                                                            COD                                                   (GAS)                                                                              (%)  1   2   1  2  1  2                                         __________________________________________________________________________    Untreated                                                                              --   77   1.32                                                                              1.32                                                                              6.08                                                                             6.22                                                                             91.6                                                                             96.3                                      water                                                                         Filtered --   97   1.22                                                                              1.25                                                                              1.46                                                                             1.46                                                                             33.5                                                                             35.5                                      untreated                                                                     water                                                                         Treatment No. 1                                                                        180  99   0.26                                                                              0.24                                                                              0.28                                                                             0.28                                                                             31.2                                                                             30.5                                      Treatment No. 2                                                                        600  99   <0.1                                                                              <0.1                                                                              1.12                                                                             1.12                                                                             22.3                                                                             23.6                                      Treatment No. 3                                                                        900  99   <0.1                                                                              <0.1                                                                              1.33                                                                             1.20                                                                             31.1                                                                             30.3                                      __________________________________________________________________________

In the results of the experiments, favorable tendency to reduction inthe amount of P was observed in a broad range of the magnetic fluxdensity. On the other hand, as to NH₄, NH₄ was reduced in a range of alow magnetic flux density, like the dephosphorizing reaction, while in arange of a high magnetic flux density, it is considered that the NH₄which had once been separated out as flocs assumes again a colloidalstate with the elapse of time and remained.

EXAMPLE 3 Example of Softening Hard Water

Experiments of removing calcium ions from the following samples whichsuffered from the deleterious effects of hard water were carried out. Atrace amount of magnesium ion, etc. was also removed in the form offlocs in the same way as in the case of calcium ions.

Samples

(a) The water of the pond in Koyama Garden (underground water)

(b) Higashi-kakogawa; the water of an agricultural irrigation pond(containing domestic waste water and agricultural effluent)

(c) Sweden; the water of Bosta-Trask (lake water)

(d) Sweden; the water of Bruns-Viken (underground water for domesticuse)

100 g of cristobalite (Akita) and a magnetic sheet having a strength of240 gausses were put into a 300-ml beaker, and 250 ml of each samplewater was added. Each beaker was covered with a watch glass and after itwas allowed to stand for 24 hours the water was filtered through GF/Ffilter paper. 50 ml of the filtrate was collected and 10 ml ofhydrochloric acid was added thereto and subjected to atomic-absorptionspectroscopy in a constant volume of 100 ml.

An appropriate amount of untreated water was collected and measured bythe atomic-absorption spectroscopy in the same way. The Ca ionconcentrations of the untreated waters and the treated waters are shownin the following table and FIG. 28.

    ______________________________________                                                     Ca ion concentration (ppm)                                       Sample         Untreated water                                                                             Treated water                                    ______________________________________                                        Bosta-Trask c      48            2.4                                          Koyama Garden                                                                             a      28            2.0                                          Bruns-Viken d      19.5          1.5                                          Higashi-kakogawa                                                                          b      17.5          1.0                                          ______________________________________                                    

In the experiments, any drinking water exhibited a favorable tendency toremoval of calcium, and it has been made clear that the technique of thepresent invention is applicable to the softening of hard water andprevention of the deposition off calcium onto the pipes or the like.

FIG. 5 schematically shows a method treating water adopting a dilutingmethod. In FIG. 5, the reference numeral (1) denotes a treating tankusing cristobalite and a magnetic field. In the treating tank (1),protons are released and a magnetic field is memorized, whereby treatedwater, i.e. treating water, is obtained. The reference numeral (9)represents a mixing tank, in which protons and the distribution of amagnetic flux are averaged, the flocculation of cations is progressed,phosphate ions are deposited, nitrogen in an organic state is adsorbedand deposited, and algae are adsorbed and deposited. The referencenumeral (10) denotes a deposition tank for carrying out deposition,aging and separation. The reference numeral (11) denotes a filteringtank, in which deposits such as aluminum phosphate, magnesium phosphate,calcium phosphate, nitrogen phosphate, iron phosphate, nitrogen in anorganic state, ammonium salts and algae are separated. These separatedsubstances are dehydrated in a deposit dehydrating tank (12) and used asagricultural fertilizers. The reference numeral (13) represents a cationadding tank for adding cations to the treating tank (1) or the mixingtank (9), as occasion demands.

EXAMPLE 4 Ion Behavior in the Various Treating Waters Diluted by VariousUntreated Waters

1. Preparation of Treating Water

(a) Treating mixed water consisting of effluent water and sea water

It can be said that eutrophicated substances flowing into inland seas,bays, bonds, lakes and marshes are caused from general domestic wastewater.

In the experiments, on the assumption that domestic waste water flowsinto sea water, treating water was prepared by pouring mixed sea water(domestic waste water and seat water which were mixed in a ratio of 1:1)into a treating tank using cristobalite and a magnetic field (220 G),and allowing the sea water to stand for 24 hours. The pH of thethus-obtained treating water used for diluting treatment was intended tobe about 5.0 to 3.0.

(b) Treating effluent water

The effluent water of the domestic waste water treating plant (HimejiCity, Ebuna Housing Development water treating plant, amount of effluentwater: 600 t/day) was treated in the same way as in the case of (a).

2. Investigation on Ion Behaviour in Diluted Water

In order to investigate ion behavior in diluted water, flocs were formedby combining the following untreated waters and treating waters, and thetendency of removal of P and N and the movement of other cations wereexamined.

Combination

450 ml of effluent water+50 ml of treating water (a)

450 ml of effluent water+50 ml of treating water (b)

45 ml of mixed sea water+50 ml of treating water (a)

450 ml of mixed sea water+50 ml of treating water (b)

450 ml of sea water+50 ml of treating water (a)

450 ml of sea water+50 ml of treating water (b)

450 ml of effluent water+50 ml of treating water (b)+50 ml of gel (26.5ppm of Al)

450 of mixed sea water+50 ml of treating water (b)+50 ml of gel (26.5ppm of Al)

450 ml of sea water+50 ml of treating water (b)+50 ml of gel (26.5 ppmof Al)

The treating time was 60 minutes for each level. When 60 minutes hadpassed after the mixture, the concentration of each ion remaining ineach filtrate was measured and the deposit was washed down into theoriginal beaker by using a wash bottle to measure the concentration ofeach ion in the deposit.

Results of Measurement

The results of the measurements are shown in the graphs of FIGS. 7 to14. In spite of the movement of pH toward the acidic side, the cationsof CaO, MgO, Al₂ O₃, Fe₃ O₄, ZnO and the like deposited and, especiallyin a weak acidic state, ions producing hydroxides reacted acutely enoughto rapidly deposit Al₂ O₃, Fe₃ O₄ ZnO and the like. On the alkalineside, ions producing hydroxides such as MgO and CaO gradually becamedeposits in a long time. The removal of P and N had a close relationwith the deposition of these cations, and especially on the acidic sideP and N acutely combined with a trace amount of (1 to 5 ppm) cationwhich produces hydroxides, thereby being removed from the water system.It is therefore essential for the removal of P and N from water that anappropriate amount of cation is contained in the treating water and/orthe untreated water, and that an appropriate amount of proton andmagnetic flux density exist. If an appropriate amount of cation does notexist in the treating water and/or the untreated water (water beingtreated), it is possible to completely remove P by adding about 1 to 5ppm of Al ions (Fe ions, etc.) to the treating water and/or theuntreated water. (It is difficult to separate not more than several ppmof cations as hydroxides by an ordinary alkali treatment).

If an appropriate amount of cation is contained in the treating waterand/or the water being treated, flocs are generated sufficiently rapidlyto achieve the object even if the pH reaches 6.5 to 6.8 after thedilution.

It has been made clear that it is possible to average the distributionof a magnetic field to a great extent by the diluting treatment. In thefollowing graphs and tables, the symbol "A" represents effluent water,"B" mixed sea water, "a" treating mixed water consisting of effluentwater and sea water, "b" treating effluent water, and "gel" Al gel.

EXAMPLE 5 Behaviour of P and N Depending upon the Dilution and AgingPeriod for Each Level

As the water being treated, the mixed sea water consisting of sea waterand the effluent water of Ebuna Housing Development mixed in a ratio of1:1 and the effluent water of Ebuna Housing Development were used.

As the treating water, "a": the mixed sea water treated in the same wayas in Example 4, "b": the treated effluent water of Ebuna HousingDevelopment, and "c": the effluent water of Ebuna Housing Developmenttreated by adding an amount equivalent to 2.65 ppm of Al gel were used.

The combinations of the experimental materials and the experimentalmethod are as follows.

    __________________________________________________________________________    No.                                                                              Water being treated                                                                      Treating water                                                                        Dilution                                                                           Aging period                                       __________________________________________________________________________    1  Mixed sea water 450 ml                                                                   a. 50 ml                                                                              × 10                                                                         0-1 day-7days-14 days                              2  Mixed sea water 485 ml                                                                   a. 15 ml                                                                              × 30                                                                         "                                                  3  Mixed sea water 490 ml                                                                   a. 10 ml                                                                              × 50                                                                         "                                                  4  Mixed sea water 495 ml                                                                   a. 5 ml × 100                                                                        "                                                  5  Effluent water 450 ml                                                                    b. 50 ml                                                                              × 10                                                                         "                                                  6  Effluent water 485 ml                                                                    b. 15 ml                                                                              × 30                                                                         "                                                  7  Effluent water 490 ml                                                                    b. 10 ml                                                                              × 50                                                                         "                                                  8  Effluent water 495 ml                                                                    b. 5 ml × 100                                                                        "                                                  9  Effluent water 450 ml                                                                    c. 50 ml                                                                              × 10                                                                         "                                                  10 Effluent water 485 ml                                                                    c. 15 ml                                                                              × 30                                                                         "                                                  11 Effluent water 490 ml                                                                    c. 10 ml                                                                              × 50                                                                         "                                                  12 Effluent water 495 ml                                                                    c. 5 ml × 100                                                                        "                                                  __________________________________________________________________________

The samples having the above-described combinations were put into therespective 500-ml conical beakers to carry out aging test.

In the analysis, the flocs generated were filtered through a GF-F filterand the T.P. and T.N. remaining in the filtrate were measured so as toexamine the effective kind of the treated water, the effective dilutingtime, and the aging effect.

The results are shown in FIG. 15.

1. In the case of mixed water+treating mixed sea water, even 100-timedilution exhibited good P and N removing effect, and the aging treatmentalso produced a good removing effect.

2. In the case of effluent water+treating effluent water, only 10-timedilution together with the aging treatment showed a P and N removingeffect. This fact shows that the lack of a deposit derived from the lackof cations lowered the adsorbing and depositing capacity.

3. In the case of effluent water+treating effluent water added with Algel water, even 100-time dilution exhibited a completely good P removingeffect, because the amount of proton was small and an appropriate amountof cation was contained after the treatment in spite of the pH of 6.7 to6.8 N removing effect was good, showing a tendency similar to the agingeffect.

From these results it has been proved that it is possible to furtherincrease the degree of dilution if the water being treated and/or thetreating water contains or is caused to contain an appropriate amount ofcation and an appropriate amount of proton is provided for flocculatingthe cations.

EXAMPLE 6 Behaviour of P and N and the Light Transmittances of the Waterof a Fish Pond Subjected to the Batch Dilution Treatment

The water of a fish pond was used as the water being treated, and as thetreating water, "a": effluent water+sea water treated in the same way asin Example 4, "b": the water of the fish pond treated in the same way asin Example 4, "b+gel": the water of the fish pond added Al gel theretoand treated in the same way as in Example 4 were used. The changes withtime in the amounts of P and N and the light transmittances in the caseof the degrees of dilution of 10 times and 20 times are shown in FIGS.16 and 17 together with the behaviour of P and N and the lighttransmittance with respect to the degree of dilution.

EXAMPLE 7 Behaviour and the Light Transmittances of the Water Subjectedto Continuous Flowing Dilution Treatment

FIG. 6 schematically shows a test plant for treating water by dilutingthe water using the treated water of the present invention. Thereference numeral (14) represents an untreated water tank, (1) thetreating tank using cristobalite and a magnetic field, (15) a sea waterand treating water tank, (16) a treating water tank, (17) a constantdelivery pump, (9) the mixing tank and (10) the deposition tank.

By using the test plant adopting a diluting method shown in FIG. 6, awater being treated and a treating water were continuously werecontinuously flown at a rate of 1,500 ml/hr and 150 ml/hr, respectively.As the water being treated, the water of a fish pond and the effluentwater (effluent water at the seivage disposal plant of Ebuna HousingDevelopment) were used, and as the treating water, a: effluent water+seawater, b: effluent water, and b+gel: effluent water+Al gel treated inthe same way as in Example 4 were used. The water being treated and thetreating water were naturally mixed in the mixing tank to produce flocsand precipitate a deposit in the deposition tank. The supernatant liquidwas caused to flow out to obtain the treating water, and the flowingvalues were measured. The value obtained by the analysis at the time ofcollecting each water was used as each of the initial values. Thesatisfactory results such as those shown in the graphs in FIG. 18 wereobtained for the removal of P and N and algae (substituted by the lighttransmittance). The results of the experiment on the continuous flowingdilution treatment are shown in the following table.

    __________________________________________________________________________                           Water of fish pond                                                                      Treated                                                             (untreated water)                                                                       water                                        __________________________________________________________________________    Hydrogen ion concentration                                                                           7.3       6.1                                          (Water temperature)                                                                            °C.                                                                          20        20                                           Suspending substance                                                                           mg/l  400       2.0                                          Chemical oxygen demand (COD)                                                                   mg/l  32        7.2                                          Biological oxygen demand (BOD)                                                                 mg/l  137       2.5                                          Total phosphour  mg/l  13.8      0.02                                         Total nitrogen   mg/l  9.24      2.56                                         Visibility       degree                                                                              5.2       >30                                          Chlorophyll      mg/m.sup.2                                                                          1,830     3.3                                          Algae            number/ml                                                                           37 × 10.sup.5                                                                     2,100                                        Temperature for collecting water                                                               °C.                                                                          26.0      26.0                                         __________________________________________________________________________

The treating water obtained by the experiment of the continuous flowingdilution treatment in Example 7 was diluted again with the water of thefish pond (×11×5 to ×11×50), and flocs were generated in the same way.The Total-P and Total-N remaining in the supernatant liquid and thelight transmittance were measured, whereby the effect remaining in thetreating water diluted by 11 times was confirmed. From the results shownin the lower part of FIG. 17, it has been proved that the diluted watershave an adequate remaining power.

As to the degree of dilution,

the treating water of the effluent water+50 ppm gel which had beendiluted by 550 times was effective, and

the treating water of the effluent water+sea water which had beendiluted by 330 times was effective.

From the above-described examples the following conclusions have beenobtained:

1. When an element has a lower pH for producing hydroxides, it has thehigher tendency for removal of ions, but even an element which produceshydroxides on the alkaline side exhibits a tendency for removal of ionsalthough the treatment of the present invention is carried out on theweak acidic side.

2. The tendencies and effects shown in the method of the presentinvention are in common with the batch treatment and the continuoustreatment.

3. In the treatment of the present invention, even a trace amount ofcation becomes a deposit and this tendency is prominent particularly inan element which produces hydroxides in a low pH range.

4. In the treatment of the present invention, cations are firstflocculated and a part of anions are adsorbed and flocculated by thecations at the time of flocculation of the cations, whereby the cationsand a part of the anions are removed from a water being treated.

5. In the treatment of the present invention, it is essential that anappropriate amount of cation (preferably 1 to 5 ppm of Fe, Al, or thelike, but the amount may be changeable and other cations may be used) iscontained in a water being treated or a treating water. Therefore, inconsideration of the treating time, method, the ion concentration in thewater being treated, the ion concentration in the treating water, andthe like, a trace amount of cation is added before treatment, ifnecessary.

6. In the treatment of the present invention, it is essential that anecessary amount of proton based on the amount of cation exists in thewater being treated or the treating water (the amount of proton in thetreating water is controlled by the treating time on the basis of the pHto be intended).

7. As a result of examining the purification treating capacity remainingin the treating water (diluted by 11 times) obtained by the continuousflowing treatment, it has been found that the protons in the treatingeffluent water have a remaining power until it is diluted by 50 times(diluted by 550 times in terms of the untreated water) and both theremaining ions and protons in the treating mixed sea water have aremaining power until it is diluted by 30 times. When the treating mixedsea water was diluted by 50 times, the ratio of the removed P wasgreatly lowered. This is considered to be because the amount of cautionbecame insufficient due to the generation of the flocs.

8. From the comparison between the characteristic values before andafter the continuous flowing test, a very effective method for theremoval of BOD, T.P. algae and chlorophyll A has been found.

EXAMPLE 8

FIGS. 1 to 4 show embodiments of an apparatus of the present invention.FIG. 1 shows a water purifying apparatus which uses the water pipe(passage pipe) (1) itself as the treating tank. The coil (2) is woundaround the water pipe (1) and energized to supply a magnetic field intothe pipe. The magnetic flux density is determined by the number of turnsof the coil. Cristobalite (6) was put into the water pipe (1) with aninsulated coat (5) provided outside the coil (2). Untreated water (7) iscaused to flow into the water pipe (2) and provided with a magneticfield by energizing the coil so as to purify the water. Air jet of 2 to5 kg/cm² and/or water is jetted periodically from the cleaning nozzles(4) to wash the cristobalite and the like. The flocs are separated inthe filtering tank, the deposition tank or an induction separation tank.

FIG. 2 shows a water purifying apparatus which uses a water flowing tank(1) as the treating tank. This is an example of an apparatus usingdiscal magnets (3) (plastic binder+ferrite magnet). On the magnet (3) Npoles and S poles are disposed alternately, the optimum space betweenthe magnets being 2 to 3 cm. They are arranged such that thedistribution of the magnetic flux is averaged as much as possible. Theconfiguration, magnetic flux density and the like of the magnet (3) arefreely selected so as to be suitable for a strong magnetic field. Theuntreated water (7) is caused to flow into the water flowing tank (1) totreat the water. Air jet of 2 to 5 kg/cm² and/or water is jettedperiodically from the cleaning nozzles (4) to wash the flocs adhered tosurfaces of the cristobalite (6) and the magnets (3). The flocs andcolloids generated are treated in the same way as in FIG. 1.

FIG. 3 shows a water purifying apparatus which uses the water flowingtank (1) as the treating tank and magnet sheets (3) with N poles and Spoles disposed alternately thereon. The magnet sheet (3) is a magnetizedplastic sheet, and it is possible to provide it with a freely selectedmagnetic flux density. The N and S poles are arranged in a reticulatestate, the optimum space between the magnet sheets (3) being 2 to 3 cm.They are suitable for a low magnetic field and accelerate the growth offlocs. Many products having a strength of 180 to 160 Gauss arecommercially available. Air jet of 2 to 5 kg/cm² and/or water is jettedperiodically from the cleaning nozzles (4) to wash the flocs adhered tothe surfaces of the cristobalite (6) and the magnet sheets (3). Theflocs and colloids generated are treated in the same way as in FIG. 1.

FIG. 4 shows a water purifying apparatus which uses the water flowingtank (1) as the treating tank and the magnet sheets (3). Thecristobalite is accommodated in rotatable cristobalite retainingcylinders (8) (cristobalite baskets) having a body portion consisting ofa net. It is easy to remove the flocs adhered to the surface of thecristobalite by rotating the cristobalite retaining cylinders, asdesired.

INDUSTRIAL APPLICABILITY

As is clear from the above explanation, according to the water treatingtechnique of the present invention, it is possible to purify all thesurrounding waters and to soften hard water in such a manner as toenable free management and control by a simple operation of selectingthe amount of proton released and the strength of a magnetic field.Thus, the technique of the present invention has an economical effect oftreating water at low equipment cost and running cost.

According to the present invention, it is possible to remove, reduce,vanish or deproliferate the cations such as P and N, a part of theanions, eutrophicated substances, chlorophyll, algae, bacteria and thelike contained in the surrounding waters by selecting the amount ofproton and the strength of a magnetic field. The present invention hasvarious advantages such as those described below.

The treating method according to the present invention brings about ahigh practical value, because the inclusion of the secondarycontaminating substances which are produced in carrying out the priorart using an adsorbent, flocculating agent, neutralizing agent,oxidizing agent, reducing agent or the like is very rare and the amountof sludge generated is very small.

Adoption of the water treating method of the present invention makes itpossible to soften hard water and remove a trace amount of heavy metaland the like contained in factory effluent or the like.

The highly activated water obtained by the water treatment of thepresent invention restrains iron from melting out of the inner wall of asteel pipe, thereby preventing the generation of iron hydroxide. In thewater treated by the present invention, the action of bacteria issuppressed, thereby preventing the generation of green algae and thelike.

When an appropriate amount of Fe ion and/or Al is contained in wastewater, both a flocculating effect with respect to green algae and a highadsorbing and depositing effect with respect to NH₄ type N, N in theorganic form, PO₄ and the like are manifested.

By diluting the treated water obtained by the present invention with awater being treated and providing an appropriate memory magnetism andcations, if necessary, it is possible to remove the cations, a part ofthe anions, chlorophyll, algae and the like from the water beingtreated.

When purifying a water being treated by diluting the treating watertherewith, purification of a large amount of water being treated isenabled by treating a small amount of water being treated, and since thetreating method is complete and purification is possible without usingany chemical agent or driving power, this method can display a largepower especially in the purification of the water in a wide area.

The water treating technique of the present invention has theabove-described many advantages in spite of a simple operation, aninexpensive equipment cost and a low running cost, and thus greatlycontributes to this field.

What is claimed is:
 1. A method of treating water containing undesirablesubstances, which comprises:soaking cristobalite in said water;controlling the pH of said water by means of said cristobalite to causesaid undesirable substances to separate out of said water; subjectingsaid water, before, during or after said soaking of cristobalite, to amagnetic field; and removing the separated undesirable substances fromsaid water.
 2. A method according to claim 1, wherein said magneticfield has a strength of about 100 to 600 gausses.
 3. A method accordingto claim 1, wherein said magnetic field has a strength of about 1,000 to2,000 gausses.
 4. A method according to claim 1, wherein said waterbeing treated is water which contains chlorophyll, algae, or a mixturethereof.
 5. A method according to claim 1, wherein said water beingtreated contains alkaline earth metal ions.
 6. A method according toclaim 5, wherein said alkaline earth metal ions are calcium or magnesiumions.
 7. A method according to claim 1, wherein said water being treatedcontains insufficient cations to generate flocs during said treatment,and sufficient cations are added to said water to generate flocs forremoving said undesirable substances.
 8. A method of treating wateraccording to claim 1, which further comprises a second treatment ofdiffusing the treated water, after said removal of said separatedundesirable substances, into additional water containing the same ordifferent undesirable substances.
 9. A method according to claim 8,wherein said additional water being treated is water containingchlorophyll, algae, or a mixture thereof.
 10. A method according toclaim 8, wherein said treated water and said additional water togethercontain insufficient cations to generate flocs during said secondtreatment, and sufficient cations are added to said treated water orsaid additional water, or both, to generate flocs for removing saidundesirable substances in said additional water.
 11. A method accordingto claim 10, wherein said additional water being treated is watercontaining chlorophyll, algae, or a mixture thereof.